561261120 has 280 divisors, whose sum is σ = 2163860544. Its totient is φ = 120741888.

The previous prime is 561261079. The next prime is 561261139. The reversal of 561261120 is 21162165.

It is a tau number, because it is divible by the number of its divisors (280).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 33015352 + ... + 33015368.

Almost surely, 2^561261120 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 561261120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1081930272).

561261120 is an abundant number, since it is smaller than the sum of its proper divisors (1602599424).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561261120 is an frugal number, since it uses more digits than its factorization.

561261120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 34 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 561261120 is about 23690.9501708986. The cubic root of 561261120 is about 824.8753383724.

The spelling of 561261120 in words is "five hundred sixty-one million, two hundred sixty-one thousand, one hundred twenty".